Sanyo dps46819

[slickrickybobby89]

Hey guys I'm working on a sanyo model # dps46819, the issue im having is distorted picture, i think the term is "solarized" i have visually inspected all components and boards, i have tested the power supply to rule it out, all voltages are correct. I cleaned and reset all conections on the set, and resoldered the ground on the tcon connector, and the problem still persists. It is solarized even when the menu is pulled up. Im wondering if anyone might be able to point out which chip would be responsible for causing this issue.

[cliff_hootarski]

Re: Sanyo dps46819

1st picture, left side, AS15, 48 pin chip.

[slickrickybobby89]

Re: Sanyo dps46819

Forgot to mention this is an intermittent problem, after the set is on for about 15 mins sometimes the screen will go back to normal, but will return to solarized after a couple minutes. There is also a buzzing noise coming throught the speakers, i figured it was related to the solarization issue.

[slickrickybobby89]

Re: Sanyo dps46819

Is there a method of testing this to verify? Thank you for your quick response cliff_hootarski. Very much appreciated.

[cliff_hootarski]

Re: Sanyo dps46819

Pictures of the "solarization"?
Try freeze spray on that AS15 to see if it changes.

[cliff_hootarski]

Re: Sanyo dps46819

Record the voltages on the "VG"(anything labeled VGxx) test points beneath the AS15 chip
when the picture is bad vs good. Let us know the values. In table form, ie

VG01 - xx Volts
VG02 - xx Volts
and so on.

[budm]

Re: Sanyo dps46819

I can see the GAMMA DC Voltage test points VG1, ... VG22 but I cannot see ALL of them on the board, some may be under the stickers.

[slickrickybobby89]

Re: Sanyo dps46819

Sorry had to reassymble the set lol.

[slickrickybobby89]

Re: Sanyo dps46819

I have to figure out how to fire this set up with the back removed, i cannot access the t-con board with everything hooked up.

[cliff_hootarski]

Re: Sanyo dps46819

That does look like a classic gamma chip fault.

[slickrickybobby89]

Re: Sanyo dps46819

Vg1 15.32
Vg2 11.47-11.61
Vg4 10.47
Vg6 10.23
Vg8 10.21
Vg10 8.76
Vg12 1.707
Vg13 7.53
Vg15 1.16
Vg17 5.27
Vg19 14.73
Vg21 13.56
Vghc 26.81
Vgl 5.992
Vgma 15.35
The chip in question is also extremely hot to the touch, and freeze spray seems to have no affect on its performance.

[cliff_hootarski]

Re: Sanyo dps46819

Bad.

[slickrickybobby89]

Re: Sanyo dps46819

Thanks a million, i will report back once i get a replacement board, my soldering skills are good, but i don't think i could pull that chip off. Thanks cliff and budm, I hope to learn more from you in the future.

[slickrickybobby89]

Re: Sanyo dps46819

Can i ask how you can tell from those values that its bad? I ask so if i run into the problem again on another set i might be able to test it myself and know without having to ask again.

[cliff_hootarski]

Re: Sanyo dps46819

The voltages should be linear. Decreasing (or increasing) little by little.
Vg1 15.32
Vg2 11.47-11.61
Vg4 10.47
Vg6 10.23
Vg8 10.21
Vg10 8.76
Vg12 1.707 BAD
Vg13 7.53
Vg15 1.16 BAD
Vg17 5.27 BAD
Vg19 14.73
Vg21 13.56
Vghc 26.81
Vgl 5.992
Vgma 15.35

[slickrickybobby89]

Re: Sanyo dps46819

Ok, i understand that now thanks alot man.

[dick_barton]

Re: Sanyo dps46819

Put your values into this spreadsheet.

https://www.badcaps.net/forum/showth...ht=gamma+excel

[slickrickybobby89]

Re: Sanyo dps46819

This set is repaired, thanks for the help guys, it was the t-con board.

[noledud]

Re: Sanyo dps46819

To any others who have this problem, instead of buying the full TCON that could be expensive i just used an AS15 repair service off ebay. There are a few people offering it and can sometimes be cheaper.

[hmendez86]

Re: Sanyo dps46819

To my recommendation change the t-con chips some times fails even if there are new...and t-con it self it might have other components in short...it's better a new t-con which in this case the problem.